Magnetic separator.



$15,823,492. :PATENTED JUNE 12,1906.

L. A. DUN A MAGNETIC SEPARATOR;

APPL IOATION FILED mm. s, 1902.

' 1 4 z snnm's-snnntr 2.

s I netic teeth i the improvement. liesin .vergences at its-surfacediagonally with respect toa line. joining the magnetic centers.

' LEWIS A. DUNHAM, OE'KANSAS CITY, MISSOURLhSSIGNOR, BY'MESNE'ASSIGNMENTS, TO INTERNATIONAL seranaron COMPANY, or CHI- 1'0 ll whom atmay concern:

.iQ'oAeo, ILLINOIS, A noRroRAnoN on NEW JERSEY,

rsaeusrio eseana'ros it known thatI, LEWIS A. DUNHAM, a citizen of'theUnited States, residing at Kansas City, in. the. county of J ackson andS tete ofiMissouri, haveinventcd aeertain new and usefiiljlmprovement inMagnetic Separate rs, (GaseNo. 1,) ofwhich the ollowing is a full,clear,v concise, and. exact description, reference being had to theaccompanying draw' ings, formmg a part of this specification.

as This-invention relates to a magnetic sepa- ,path diver entirom theless 'ratorof the type in which the material to be separated is passedbetween a movable carrier, such asr'a rotating cylinder, and an opposingimagneteplole, the carrier having mager means for producing convergencesof the lines of force toward its surface, saidc'arrierandpole-piecebeing so dis posed that the more permeable particles of.

material inthe mixture are carried into a ermeable particles, whic areallowed to fall away.

The object of this invention is to produce a more efiectiveseparation,especially in treating materials of very low permeability, and thecombination with such a separator of means for maintaining the maximummagnetic flux suhstantially undimiin's'hed through an extended range ofmovement of the materials undergoing separation below and beyond thepoint where the unattracted material is first free to fallaway fromtheattracted material. 'As

'an example of suchmeans; there may. be'provided in combination with ahollow separatv ,ir1g-cylind'er and a magnet-pole facing the outer sidethereof a second. magnet-pole inside the cylinder and offset withrespect to eabiia lS-held by the undir'ninish said outer pole, so as todistort downwardly themagnetic flux from said outer pole and concentratethe same upon the cylinder along a-segment which liesbelow and beyondthe segment immediately facing said outer pole. In such construction therotation ot the cylinderflwill therefore move the flux con of the twopole-pieces. The result is that after the --un'attra'cted material isfree to fall the attracted material even of verylow per- 1n magneticflux in a path divergent from said falling unattracted material until ithas passed Specification of Letters "Patent,- 1 Application filedDecember 8,1902. smart. 134,288.

Patented June 12, 1906.

beyond a point where a divider may main tain the separation. In otherwords, thev v magnetic field'is extended in the direction of movementofthe magnetic teeth carrying the attracted material, so as to greatlyincrease the distance. through which any particular tooth may be moved"without materially re ducing the 'fiux through. such tooth, thus holdingthe attracted material until it is widely'separated from the materialnot attracted.

In the. accompanying drawings, Figure 1 is a side elevationof theseparator. 'Fi 2 is a sectional'plan view thereof, taken on line 2 2 ofFig. 1. Fig. 3 is a sectional elevation taken on line 3 3 of Fi 2, andFig; 4 is an enlarged sectional view diagrammaticallyillustrating thedistrihuti on of the efiective magnetic field.

The same referencecharacters designate; the same parts in all thefigures.

The separator consists in its elements of a" cylinder mounted to rotatebetween oppos- 7 5 in magnet-poles. In the form shown the' cy inder ishollow, and a magnet 4 is mounted inside said cylinder, extendingdiametrically across the same and having its pole-faces 5 6 facing theinner peri hery thereof. The energizing-winding 9 is s own as wound uponthe inner magnet 4 between said poleefaces 5- 6. An' iron yokepiece l.surrounds the separating-cvlinder and is provided with poles 28 24,facing the opposite sides thereof. 8 5

As will be noted, the inner' magnet iis angularly disposed withreference to the 'outer pole-pieces 23 24, so that the inner pole-face 5is offset with respect, to the outer polepiece 23 and has 'the effect ofdistorting 9o downwardly the magnetic flux of said outer pole, as shownmost clearly in Fig. i. The

magnctscore 4 issupported by an angularlyadjustable shaft 7, a set-screw8' being pro vided tov hold the shaft andcore in adjust- 5 ment. e r

The separating-cylinder is made up of a framework or cage comprisingtransverse rods 13 13, extend1m betweentheend plates 10 1'0, andsegmentdlplates' or laminae, hav 10o ingteeth' or projections 14 14 ontheir outer edges, said plates being assembled between the transverserods 13 13 to build 11) the body of the cylinder. It will be noticedthat the construction of the cylinder is such as to re 5 readily permitthe passage of magnetic lines radially through the body thereof,although the longitudinal gaps between. the rows of toothed platesinterpose a considerable reluctance to the passage of a magnetic fluxcircumferentially through the cylinder. The teeth upon the segmentalplates are adapted to cause local eonvergences of the magnetic fluxtoward the surface of the. cylinder built up thereby.

The cylinder is provided with by which it may be rotated, the rotationbeing indicated by the arrow 1.8 in Fig. 3. The material to be separatedis received by a hopper 15 and is fed through the spout 16 thereof ontothe surface of the rotating cylinder, which carries the same past themagnetole 23. A shield 17 is provided to prevent t iie materials frombeing thrown off the carrier centri'lugally. Collectors 20 and 22 are)rovided underneath the cylinder to receive t e separated products.

The magnet having been energized by current from the dynamo 19 passingthrough the coil 9, there is set 11' a magnetic flux r adially throughthe cylinr or between the inner magnet at and the outer pole-pieces 23and 24, respectively. The flux is diagrammatically ndicated by dottedlines in Fig. 4. The projecting iron teeth cause convergences of thelines of force, as shown. The more permeable particles of materialpassing over the cylinder are attracted to the teeth is and held therebyuntil they are carried past the dividing-point between he collectors 20and 22, said attracted particles being finally discharged into thecollector 22 after having been carried )ast the region of intense magapulley 253, direction of netic field. he non-magnetic material, be-

ing unattracted by the cylinder, falls over the side thereof into thecollector 20.

In machines of the t pe under consideration in order efiectua ly toseparate mag netic materials of low permeab lity from a mixturecontaining materials still lower permeability it is necessary that avery intense magnetic flux be provided and that the attractive forcethereof shall be exerted at an eilicient angle to the force of gravityso that the unattracted material may. fall away from the attractedmaterial. in machines of this character heretofore constructed there hasbeen great diiliculty in maintaining a suliiciently intense magneticiiuX throughout such-an extended range of movement of the attractedmaterial after the nonmagnetic 'material is free to fall that a dividerdate can be placed between the two classes oi inaterial. In order toe'liect a separation, the non-attracted material must be free to fallaway from the attracted material, and it has been difficult to establisha magnetic flux of suflicient intensity acting at the required angle tothe force of gravity and through a suiliciently-extended rangeofmovement of the materials Without placing a magnet-polc of an opposinin such position as to interfere with the free fall of the unattrnctedmaterial.

In accordance with the present invention the inner magnet 4 is adjusted.to an inclined position, as shown in Figs. 3 and 4, so that the innerpole 5 will face anarc on the inner periphery of the cylinderconsiderably oilset below the arclaced by the outer pole-piece Themagnetic flux is thereby distorted downwardly, so as to be concentratedalong a considerable arc oi the cylinder below the horizontal diameterthereof, While the outer polo-piece 23 does not extend into the path ofmaterial falling vertically downward over the side of the cylinder. Onaccount of the downward distortion of the 11 rain body of magnetic fluxthe magnetic tecili carrying the attracted material move diagonally withrespect to the'mean direction of the flux, and so the magneticsaturation of the teeth is in aintaincd to the rerniired degreetl'n'ough an extended range of movement below and. be yond the place ofseparation-that is, the place where the unattracted material is firstfree to fall. away from the attracted material. By this means theattracted material, even of very low permeability, hold by the carrieruntil it is carried a considerable distance from the place ofseparation, this result being accomplished without interfering with thefree fall of the material not attracted.

The density of the magnetic flux through the cylinder rapidly decreasesin the direction of rotation of the cylinder beyond the lower edge ofthe pole-piece 5, so that the material attracted to the cylinder isreleased shortly after passing beyond the arc of its path iaced by saidpole-piece 5 and fal s into collector .22.

The invention claimed is l. A magnetic separator comprising a movableseparatingcarrier having means for causing convergenccs of magnetic fluxtoward its surface, magnet-pole facing said carrier, and means forpassing material to be separated downwardly through the air-gap betweensaid carrier and said pole, in combination with means for downwardlydistorting the magnetic flux between the pole and said carrier.

A magnetic separator comprising a cylinder rotatable upon asubstantially horizontal axis, and a magnet-pole facing the side of saidcylinder, in combination with means for maintaining a magnetic flux ofmaximum densit, between said pole and said cylinder throughout anextended are on the surface of said cylinder below and beyond the loweredge of said magnet-pole.

3. in a magnetic separator, the combination with a magnetic cylindermounted to retate upon a substantially horizontal axis, said cylinderhaving means for causing convergences of me. :tic flu toward itssurface, .xguet-pole facing the side of trated magnetic flux from theouterpole is rated throu h the gap tion with a ho said cylinder andlying outside a vertical lane tangent to sald cylinder, and "means ordistoitlng the flux from said pole down-- wardly along the under surfaceof said carandsaid pee-piece, and a magnetole facing the inner surfaceof saidcylin er along an arc ofiset obliquely below the are faced by;said outer pole-piece; whereby the concen' distorted ownwardly towardthe under surface of the cylinder, While a clear space is left below forthe free fall of the unattracted material.

' 5. In a magnetic separatorgthe' cornbina J tion with a hollow-separat'of magne t pole-pieces outside an inside ofsaid. cylinder respectively,said pole-pieces' heing offsetiwith reference to each other.

tion with magnet pole-pieces, of- -means for causing a convergence n themagnetic flux between said pole-pieces, and): means for moving saidconvergence obliquely with res ect to a line joining the magneticcentersof tion begins.

a "'35 In wi-tness whereof I hereunto. subscribe my name" this 6thdayofJDecember,

' 6. In a magnetic separatonthe' combma-j I t e 'ole-pieces,-saidpole-pieces being formed to 'e outside a vertical plane extendingdownwardly from the place at whichseparav '1

